Build a Support Ticketing System in Microsoft Sharepoint

We need to create a support ticketing system where employees must log into our Microsoft organization's SharePoint to submit a ticket with their existing Microsoft credentials. We would have multiple routing based on the issue an employee is having, ie. departments. When an employee submits a ticket, multiple support staff would be notified via email. The employee would receive a bounce-back that their ticket has been received and they can review their ticket process update online. The employee should be able to attach files to the ticket, ie. video, pictures, and audio. Limit the size to 25 MB. Support management should also be able to assign specific tickets. Thank you.